1. Field of the Invention
The present invention relates to gas barrier substrates, which have gas barrier properties, and to methods for manufacturing the same.
2. Description of the Related Art
Conventionally, gas barrier substrates that include a resin layer and an inorganic material layer on the resin layer and have the characteristic of not allowing the passage of gases such as oxygen and moisture (so-called gas barrier properties) are used as packaging for foods and medicinal products, and as the substrates of electrical components. Examples of electrical component substrates include display panel substrates for organic electroluminescence (hereafter referred to as “organic EL”) display devices.
In organic EL display panel substrates, a gas barrier layer made of an inorganic material such as silicon oxynitride (SiON) is formed on a resin layer.
An organic EL display panel is produced by forming an anode made of a transparent material, an organic functional layer containing an organic compound that has electroluminescence characteristics, and a cathode in that order on the gas barrier layer of the gas barrier substrate.
In an organic EL display panel of the above-described structure, since moisture and gases such as oxygen that have passed through the resin layer of the gas barrier substrate are blocked by the gas barrier layer, these gases cannot penetrate the organic functional layer. Therefore, this prevents the occurrence of non-light-emitting areas (so-called dark spots), which are a form of deterioration of the organic functional layer caused by these gases (for example, see Akira Sugimoto, Development of Organic EL Film Displays, Optronics, 2001, Issue 3, pp. 122-126).
Peeling off occurs between the gas barrier layer and the resin layer due to external causes such as heat and an impact force being applied from the outside to the layers, since the adhesiveness between the gas barrier layer and the resin layer in the above-described gas barrier substrate is insufficient, and the peeling off damages the gas barrier layer. Gases penetrate any of these damaged areas so that the gas barrier properties of the layer cannot be maintained and dark spots are produced.